systemd is a system and service manager for Linux, compatible with SysV and LSB init scripts. systemd provides aggressive parallelization capabilities, uses socket and D-Bus activation for starting services, offers on-demand starting of daemons, keeps track of processes using Linux control groups, supports snapshotting and restoring of the system state, maintains mount and automount points and implements an elaborate transactional dependency-based service control logic. (http://www.freedesktop.org/wiki/Software/systemd/).

Deprecated or removed

Apart from the software obsoleted by systemd, other notable departures include:

Eclipse (now in a separate 'developer toolset' - which SL seems to have anyway so maybe there weill be no change there for us)

gcj

ecryptfs

webalizer

pidgin - replaced by empathy

HAL - replaced by udev, which is now part of systemd

thunderbird - replaced by evolution

xorg-x11-twm

xorg-x11-xdm - replaced by gdm

mod_perl - replaced by mod_fcgid

busybox - apparently not replaced by anything

Some notable deprecated systems include:

the ext2 and ext3 filesystems, in favour of ext4

sendmail, in favour of postfix

lvm1 in favour of lvm2

prelink

Network

The traditional /etc/sysconfig network scripts are deprecated in favour of NetworkManager, which gains a command line interface nmcli.

The release includes firewalld (dynamic firewall configuration), chrony (updates the system clock on frequently suspended or disconnected systems), DNSSEC (DNS security extensions to verify server responses) and OpenLMI (a common system management interface).

"Network Teaming" is introduced as an alternative to bonding.

Development

gcc 4.8.x series

glibc libraries 2.17

gdb 7.6.1

Ruby 2.0.0

Python 2.7.5

The default JDK is OpenJDK7 and the default Java is Java 7. Multiple versions can be installed in parallel.